This invention relates to a signal processing method and apparatus for processing an information dropout portion, such as clipped portion, of a continuous signal, such as an acoustic signal portion into a valid signal, and a recording medium having recorded thereon a signal processed by the method and/or apparatus.
For recording audio signals, a method is currently employed in which, for achieving satisfactory recording, a recording level thought to be optimum is set at the time of rehearsal preceding live recording.
However, with the system of pre-setting an optimum recording level, if the recording level is set to a higher value, the maximum recording level is occasionally exceeded for a larger input signal level. The portion of the input signal in excess of the maximum recording level is removed by clipping.
Clipping as referred to herein herein means rounding signals exceeding a maximum positive value D.sub.max or a negative maximum value D.sub.min of a digital signal. Such a digital signal is produced by sampling and quantization of an input analog signal shown in FIG. 1 and which is shown in FIG. 2, to maximum values D.sub.max and D.sub.min, respectively. The maximum values D.sub.max and D.sub.min are herein referred to maximum levels, respectively.
A signal reproduced from such clipped signal gives a psycho-acoustically undesirable distorted sound.